I find drinking a lot of water keeps me alert. I read that the brain uses a lot of water so I started drinking water and trying to stay hydrated at all times. Not sure if its placebo or it actually works.
I have also started meditating recently and I find it very good to relax before I go to sleep. It also keeps me happy and sane.I use this site, I haven't upgraded to the paid version.
I find the below a good blog for productivity and well being articles.